This paper focuses on Ireland's ambitious target for 2020 to reduce greenhouse gas (GHG) emissions by 20% below 2005 levels for sectors not covered by ETS (Non-ETS). Ireland is an interesting case study due to the role of agriculture (a particularly challenging sector with regard to GHG emissions reduction), that represents 29% of Ireland's GHG emissions compared with less than 10% for the EU. The analysis is carried out with the Irish TIMES model, a bottom-up energy systems modelling tool with detailed characterization of Ireland's energy system. The paper uses scenario analysis to provide pathways that demonstrate how Ireland can meet the non-ETS target at least cost. The paper considers the impacts (in terms of different technology choices and higher marginal abatement costs) arising from higher targets for the energy system to compensate for growth in agriculture activity and low mitigation potential in that sector. The results point to a need to reconsider Ireland's renewable energy focus, with a need for increased effort in renewable transport and renewable heat in particular. The results also point to significant electrification of residential heating. The results also point to a high marginal abatement cost ((sic)213/tCO(2)), which challenges the analysis carried out at EU level to establish Ireland's non-ETS target. (C) 2013 Elsevier Ltd. All rights reserved.